1. Field of the Invention
The invention generally relates to portable basketball systems and, more particularly, to a portable basketball system having dual ballast tanks where one of the tanks is movable between a compact position for shipping/storage and an expanded position providing a larger footprint to provide greater support and stability during play.
2. Related Art
Various types of portable basketball systems have been proposed and used in the past. Such proposals have recognized that stability, and in some instances portability, are desirable characteristics. However, stability and portability can present conflicting design considerations. Presently, to provide both stability and portability, portable basketball systems have a complex structural arrangement and a larger base, both of which are undesirable characteristics with respect to manufacture, cost efficiency, and storage/shipping.
These problems may be present to some degree in smaller applications like pool side and youth sports products, however, overcoming the conflicting design considerations of stability and portability is a more difficult task in designing larger units for adults and regulation play, which must be able to withstand heavier loads and more aggressive conditions. Moreover, the recent trend towards using larger and larger backboards in portable systems designed for regulation play has exacerbated these problems.
Conventionally, portable basketball systems of this type have included several main components: a basketball backboard supporting a basketball goal and a net; a pole and extension arm, elevator, or other mechanism for supporting the backboard on the pole; and a base for supporting the pole. Typically, ballast material such as water or sand is provided on top of or inside the base section to weigh down the unit, and provide the requisite stability during use. An example of a support system in which weights are provided on top of a base is disclosed in U.S. Pat. No. 4,869,501 to Anastasakis. An example of one of the first portable systems having ballast inside a base is described in the assignee's prior U.S. Pat. No. 5,207,407 to Fitzsimmons et al.
In Fitzsimmons et al. '407, a hollow tetrahedral base supports the pole and has an interior space for receiving ballast material. The support pole is secured at an angle at a rear portion of the base, so that the backboard mounted on the pole extends beyond the base and over the playing surface. A roller provided in a recess on a leading edge of the base facilitates moving the unit from one location to another. While the support assembly described in Fitzsimmons et al. '407 worked well and was portable, the size of the tetrahedral base made it inconvenient to store and ship in practice, even though the base consisted of two smaller symmetrical sections.
An improvement over this portable goal assembly is described in U.S. Pat. No. 5,415,393 to Fitzsimmons et al., also developed by the assignee of this application. Like the above-described unit, Fitzsimmons et al. '393 utilizes a hollow base that is filled with ballast material and the support pole is mounted on a rear portion of the base at an angle. However, the base of the '393 patent is much smaller in height and flatter than the prior tetrahedral base design. Moreover, the base is made from a single body rather than in two sections, and a separate support arm for the pole formed as a planar member is pivotally attached to the front end of the base. The support arm could be collapsed onto and nested on top of the base, as shown in FIGS. 1-2 of the '393 patent, thereby enabling the two-piece support system to occupy a smaller space when disassembled than when assembled, without sacrificing the stability needed for use. Thus, in practice, the unit of the '393 patent was easier to ship and store than that in the original '407 patent.
A further improved portable goal system is manufactured and sold by the assignee of this application under the CENTER COURT name. The CENTER COURT portable unit is similar to that disclosed in the '393 patent in many respects, including the base, which also is substantially flat and hollow, the rearwardly disposed angled pole, and the support pole pivotally attached to the front end of the base. However, the support pole in the CENTER COURT design is not a planar support arm, as in the '393 patent. Instead, two individual support arms formed as struts are pivotally attached to opposite sides of the front end of the base. The strut members are a less expensive alternative to the planar support arm of the '393 patent, and do not result in an appreciable loss of overall stability. Thus, the CENTER COURT unit has the advantage of being lighter in weight and more compact than the portable system of the '393 patent, without sacrificing stability.
Examples of other conventional, but less desirable, portable basketball systems can be found in U.S. Pat. Nos. 5,259,612, 5,248,140 and, 5,354,049 to Matherne et al.; and U.S. Pat. No. 5,556,088 to Mower et al. These patents disclose portable units also having a hollow base into which ballast material, such as water or sand, is disposed. However, in these patents, the pole is mounted vertically in the front portion of the base, and the support arms extend at an angle from the pole to the rear of the base. By setting the pole in the front of the center of gravity of the base in these units, it is easier to topple or "pullover" these units than the rear mounted pole units described above when applying downwardly directed force on the rim of the goal, which is a standard way to measure the stability of a portable unit.
Recently, less expensive portable basketball systems having front-mounted poles have become popular. One known inexpensive portable basketball system addresses this forward "pullover" problem experienced with a front-mounted pole by concentrating ballast in the rear of the base. In particular, a rearwardly extending base is formed by a metal frame with a tray at the rear. Two woven bags are provided, each to be filled with approximately 60 pounds of sand. The sand bags are positioned in the rear tray to stabilize the portable basketball system. However, because the ballast is rearwardly disposed, the system has a tendency to pullover backward.
An improved inexpensive, rear-concentrated portable system is manufactured and sold by the assignee of this application under the EZ COURT name. The EZ COURT system includes a base with a metal frame base and uses two ballast fillable tanks rearwardly mounted to the frame instead of sandbags. The frame expands outwardly and rearwardly from the pole. Thus, relatively wide ballast fillable tanks are used to concentrate ballast in the rear.
In the foregoing and other conventional goal units, achieving the greatest amount of stability, as measured by the amount of "pullover" force, should always be one of the paramount objects of a portable basketball system manufacturer. One approach to achieve this object is simply to use as much ballast as is practical. However, there are drawbacks to this approach, in that the more ballast to be used, the larger the base must be to accommodate the ballast. In the prior designs in which the base is hollowed to receive ballast, an increase in the amount of ballast necessitates an increased interior volume for the base, which can be accomplished by increasing the surface area, i.e. the footprint, of the base or its height. In the prior designs in which ballast sits on top of the base, it is likely necessary to provide a greater surface area for the base or to increase its strength to accommodate increased ballast. Increasing the size and/or strength of the base, in either type of design, disadvantageously increases the shipping costs, and increases the amount of storage space the unit will occupy.
One portable basketball system manufactured and sold by the assignee of this application under the HYDRO name, and which also is the subject of parent application Ser. No. 08/593,322, addresses these competing concerns by providing a separate ballast tank engageable with a non-ballast fillable base in two different positions. In one position, the separate ballast tank is engaged with the base to produce a compact configuration for shipping/storage and in the second position the tank is engaged with the base in an expanded position providing an increased footprint for greater support and stability for play.
Although this unit works well and achieves advantages over the prior art, there remains a need for a portable basketball system that can be shipped even more compactly, and can support the pole, backboard, and goal in an even more stable position during play without the danger of the portable basketball system tipping or moving than heretofore achievable. More particularly, there is a need for a portable basketball support system that provides greater stability and can carry heavier loads than heretofore practical without increasing the shipping/storage footprint of the system, and without sacrificing portability.